Function holochain_wasmer_guest::host_call[−][src]

pub fn host_call<I, O>(
    f: unsafe extern "C" fn(_: GuestPtr) -> Len, 
    input: I
) -> Result<O, WasmError> where
    I: Serialize + Debug,
    O: DeserializeOwned + Debug, 

Given an GuestPtr -> Len extern that we expect the host to provide:

  • Serialize the payload by reference
  • Write the bytes into a new allocation
  • Call the host function and pass it the pointer to our allocation full of serialized data
  • Deallocate the serialized bytes when the host function completes
  • Allocate empty bytes of the length that the host tells us the result is
  • Ask the host to write the result into the allocated empty bytes
  • Deserialize and deallocate whatever bytes the host has written into the result allocation
  • Return a Result of the deserialized output type O